Association of Central Adiposity and Metabolic Markers With Osteopenia and Osteoporosis in Chinese Adults: A QCT-Based Cross-Sectional Study

Aim: To investigate the associations between novel anthropometric and metabolic indices and the presence of osteopenia and osteoporosis in middle-aged and older Chinese adults and to identify the most effective indicators for early screening of reduced bone mineral density (BMD). Methods: A cross-sectional study was conducted among 10,142 Chinese adults aged ≥45 years who underwent quantitative computed tomography (QCT) for lumbar spine BMD assessment. The participants were classified into the normal, osteopenia, and osteoporosis groups. Anthropometric indices, including weight-adjusted waist index (WWI), relative fat mass (RFM) , and A Body Shape Index (ABSI), as well as metabolic markers, such as the triglyceride-glucose (TyG) index and glycated hemoglobin (HbA1c), were evaluated. Associations and predictive capabilities were assessed using multivariable logistic regression and receiver operating characteristic (ROC) curve analyses. Results: The overall prevalences of osteopenia and osteoporosis were 35.14% and 14.05%, respectively. Higher rates of osteoporosis were observed among females, older individuals, and those with a lower body mass index (BMI) (all P < 0.001). After adjusting for confounders, WWI, ABSI, RFM, TyG index, and HbA1c were found to be independently associated with osteopenia and osteoporosis. Among all the indices, WWI demonstrated the highest predictive value for osteoporosis (area under the curve = 0.726), followed by RFM and ABSI. In contrast, BMI and the visceral adiposity index (VAI) showed no significant associations with low BMD. These findings emphasize the importance of central adiposity and metabolic dysfunction as independent determinants of bone health. Conclusion: Among the anthropometric and metabolic indices evaluated, WWI showed the strongest predictive performance for osteoporosis, followed by RFM and ABSI. The waist-to-height ratio, waist-to-hip ratio, body adiposity index, and TyG index showed moderate predictive values, whereas traditional indicators such as BMI and VAI were not significantly associated with reduced BMD. These findings support the clinical relevance of incorporating central adiposity- and insulin resistance-related indices, particularly WWI, into early screening strategies for osteoporosis in aging Chinese populations.